Added recursion exercises.

4 files changed, 175 insertions, 2 deletions

diff --git a/python/problems/introduction/ballistics/sl.py b/python/problems/introduction/ballistics/sl.py
index b0f33e7..d4e03eb 100644
--- a/python/problems/introduction/ballistics/sl.py
+++ b/python/problems/introduction/ballistics/sl.py
@@ -15,7 +15,7 @@ bo letela krogla.</p>
 Poskusi, kako daleč gre pod kotom 45 in kako daleč pod 46 stopinj -- po 45 mora leteti dlje. 
 Preveri tudi kot 50 stopinj: če pod tem kotom leti nazaj (razdalja je negativna), 
 si ga gotovo nekje polomil.
-<p><i>Opomba: za pravilno delovanje moraš v programu najprej prebrati kot in potem hitrost.</i></p>
+<p><i>Opomba: za pravilno testiranje moraš v programu najprej prebrati kot in potem hitrost.</i></p>
 '''
 
 eval_expression = ['''\
@@ -56,7 +56,7 @@ hint = {
     'radians': ['''\
 <p>Poskusi <code>sin(30)</code>. Zakaj je rezultat negativen?</p>''',
                 '''\
-<p>Vse triginometrične funkcije sprejemajo kot v radianih in ne v stopinjah.</p>''', 
+<p>Vse triginometrične funkcije sprejemajo kot v radianih in ne v stopinjah.</p>''',
 ''' <p>V stopinjah ima cel krog 360°, v radianih pa \( 2 \\pi \). </p>''',
 ''' <p>Formula za pretvorbo med stopinjami in radiani je: </p>
 <pre>
diff --git a/python/problems/introduction/leap_year/common.py b/python/problems/introduction/leap_year/common.py
new file mode 100644
index 0000000..7dc7318
--- /dev/null
+++ b/python/problems/introduction/leap_year/common.py
@@ -0,0 +1,93 @@
+from python.util import has_token_sequence, string_almost_equal, \
+    string_contains_number, get_tokens, get_numbers, get_exception_desc
+from server.hints import Hint
+import re
+
+id = 20107
+number = 7
+visible = True
+
+solution = '''\
+leto = int(input("Vnesi leto: "))
+if leto % 4 == 0 and (leto % 100 != 0 or leto % 400 == 0):
+    print("Je prestopno")
+else:
+    print("Ni prestopno")
+'''
+
+hint_type = {
+    'mod_expression': Hint('mod_expression'),
+    'printing': Hint('printing'),
+    'name_error': Hint('name_error'),
+    'unsupported_operand': Hint('unsupported_operand'),
+    'final_hint': Hint('final_hint'),
+}
+
+def test(python, code):
+    # List of inputs: (expression to eval, stdin).
+    test_in = [
+        (None, '1900\n'),
+        (None, '1950\n'),
+        (None, '2000\n'),
+        (None, '2016\n'),
+        (None, '2100\n'),
+    ]
+    test_out = [
+        "Ni prestopno",
+        "Ni prestopno",
+        "Je prestopno",
+        "Je prestopno",
+        "Ni prestopno"
+    ]
+
+    # List of outputs: (expression result, stdout, stderr, exception).
+    answers = python(code=code, inputs=test_in, timeout=1.0)
+    outputs = [ans[1] for ans in answers]
+
+    n_correct = 0
+    tin = None
+    for i, (output, correct) in enumerate(zip(outputs, test_out)):
+        if correct in output:
+            n_correct += 1
+        else:
+            tin = test_in[i][1]
+            tout = correct
+
+    passed = n_correct == len(test_in)
+    hints = [{'id': 'test_results', 'args': {'passed': n_correct, 'total': len(test_in)}}]
+    if tin:
+        hints.append({'id': 'problematic_test_case', 'args': {'testin': str(tin), 'testout': str(tout)}})
+    if passed:
+        hints.append({'id': 'final_hint'})
+    return passed, hints
+
+def hint(python, code):
+    tokens = get_tokens(code)
+
+    # run one test first to see if there are any exceptions
+    test_in = [(None, '212\n')]
+    answer = python(code=code, inputs=test_in, timeout=1.0)
+    exc = answer[0][3]
+    exc_hint = get_exception_desc(answer[0][3])
+    if exc:
+        if 'NameError' in exc:
+            return [{'id':'name_error', 'args': {'message': exc}}]
+        elif 'not callable' in exc:
+            return [{'id':'not_callable', 'args': {'message': exc}}]
+        elif 'unsupported operand' in exc:
+            return [{'id':'unsupported_operand', 'args': {'message': exc}}]
+        elif 'TypeError' in exc:
+            return [{'id':'unsupported_operand', 'args': {'message': exc}}]
+        else:
+            return exc_hint
+
+    # if token % not in code, we have to teach them how to
+    # evaluate expressions.
+    if (not has_token_sequence(tokens, ['%'])):
+        return [{'id' : 'mod_expression'}]
+
+    # student is not using print function
+    if not has_token_sequence(tokens, ['print']):
+        return [{'id' : 'printing'}]
+
+    return None
diff --git a/python/problems/introduction/leap_year/en.py b/python/problems/introduction/leap_year/en.py
new file mode 100644
index 0000000..a2419f9
--- /dev/null
+++ b/python/problems/introduction/leap_year/en.py
@@ -0,0 +1,15 @@
+name = '*Leap year'
+
+description = '''\
+<p>Write a program that reads a number representing a year and determines whether
+this is a leap year. A leap year is divisible by 4, but not divisible by 100,
+except if it is divisible also by 400. Thence years 2004, 2008, and 2000 are
+leap years, while 2005 and 2100 are not.</p>'''
+
+hint = {
+    'plan': '''\
+<p>(translation missing)</p>''',
+
+    'no_input_call': '''\
+<p>(translation missing)</p>''',
+}
diff --git a/python/problems/introduction/leap_year/sl.py b/python/problems/introduction/leap_year/sl.py
new file mode 100644
index 0000000..236e761
--- /dev/null
+++ b/python/problems/introduction/leap_year/sl.py
@@ -0,0 +1,65 @@
+import server
+mod = server.problems.load_language('python', 'sl')
+
+name = '*Prestopno leto'
+
+description = '''\
+<p> Napiši program, ki preveri ali je leto prestopno. Leto je prestopno,
+ če je deljivo s 4, razen v primeru, ko je deljivo s 100,
+ takrat leto ni prestopno, razen takrat, ko je deljivo s 400,
+ takrat je leto prestopno. Tako so leta 2004, 2008 in 2000 prestopna,
+ leti 2005 in 2100 pa ne. </p>
+
+ <p> Če je leto prestopno, naj izpiše "Je prestopno", če ni, "Ni prestopno". '''
+
+printing = ['''\
+<p>V Pythonu izpisujemo s funkcijo <code>print</code>.</p>''',
+            '''\
+</p>Če želimo izpisati več elementov, jih ločimo z vejico.
+Imejmo spremenljivko <code>ime</code>, ki vsebuje naše ime, potem:
+<pre>
+print("Ime mi je", ime, ".")
+</pre>''']
+
+mod_expression = ['''\
+<p>Ostanek pri deljenju dobiš z operatorjem %.''']
+
+plan = ['''\
+<p>1. Preberi vrednost 2.izračunaj 3.izpiši.</p>''',
+        mod_expression,
+        printing
+
+]
+hint = {
+
+    'mod_expression': mod_expression,
+
+    'printing': printing,
+
+    'name_error' : [
+        mod.general_msg['error_head'],
+        mod.general_msg['general_exception'],
+        mod.general_msg['name_error'],
+        '''\
+<p>Verjetno uporabljaš spremenljivko, ki nima vrednosti. Ali v izrazu za
+izračun uporabljaš napačno spremenljivko? Ali pri izpisu morda poskušaš
+izpisati napačno spremenljivko?</p>'''
+    ],
+
+    'unsupported_operand' : [
+        mod.general_msg['error_head'],
+        mod.general_msg['general_exception'],
+        mod.general_msg['type_error'],
+        '''\
+<p>Verjetni razlog: funkcija <code>input</code> vrača vrednost tipa niz, ki jo
+moramo najprej pretvoriti v tip <code>int</code>, če želimo z njo
+računati:</p>
+<pre>
+v = int(input(" ...
+</pre>''',],
+
+    'final_hint' : [
+            '''\
+<p>Odlično, program deluje!<br>
+''']
+}